Field of the Invention
The invention relates to a photosensitive resin composition, a color filter, and a liquid crystal display element thereof. In particular, the invention relates to a photosensitive resin composition for a black matrix, a color filter, and a liquid crystal display element thereof having good resolution, good heat resistance, and good reliability under high temperature and high humidity.
Description of Related Art
Recently, with the development of various liquid crystal display (LCD) technologies, to increase the contrast and the display quality of the current LCD, a black matrix is generally disposed in the gap of the stripes and the dots of the color filter in the LCD. The black matrix can prevent issues such as decrease in contract ratio and decrease in color purity caused by light leakage between pixels.
The material used by the black matrix is generally an evaporated film containing chromium or chromium oxide. However, when using the evaporated film as the material of the black matrix, disadvantages exist such that the process is complicated and the material is expensive. To solve these issues, a method of forming a black matrix by using a photosensitive resin composition through photolithography has previously been proposed.
With the rising demand for the shading of the black matrix, one of the solutions has been to increase the usage amount of the black pigment to increase the shading of the black matrix. For instance, JP 2006-259716 discloses a photosensitive resin composition for a black matrix containing a high usage amount of each of a black pigment, an alkali-soluble resin, a photopolymerization initiator, a reactive monomer having a difunctional group, and an organic solvent. It should be mentioned that, the reactive monomer having a difunctional group can improve the reaction between compounds to form a fine pattern. As a result, when increasing the light-shielding property in the photosensitive resin composition by increasing the usage amount of the black pigment, the sensitivity of the photosensitive resin composition can still be maintained.
Moreover, JP 2008-268854 discloses a photosensitive resin composition for a black matrix. The photosensitive resin composition contains an alkali-soluble resin having a carboxylic acid group and an unsaturated group, a photopolymerizable monomer having an ethylenically unsaturated group, a photopolymerization initiator, and a black pigment with a high usage amount. In the photosensitive resin composition for a black matrix, a specific alkali-soluble resin is used to improve the resolution of the photosensitive resin composition having a high usage amount of black pigment.
Although in the current technique, light-shielding can be increased by increasing the usage amount of the black pigment in the photosensitive resin composition, the current photosensitive resin composition still has issues such as poor resolution, poor heat resistance, and poor reliability under high temperature and high humidity. Accordingly, the development of a photosensitive resin composition for a black matrix having good resolution, good heat resistance, and good reliability under high temperature, and high humidity is still needed.